Next Step : Canada's Dilemma: A Nation Divided? : Tempers are flaring over a referendum designed to keep Quebec in the fold. It may be the vote of a lifetime.

CALGARY, Canada — High in his 36th-floor executive suite, overlooking the neat line where the trees and houses of this city greet the vast, tawny expanse of Alberta prairie, oilman Kent Jespersen is girding for the political battle of his life.

"I think this vote is the most important vote that Canadians will have to cast, at least in my lifetime," says Jesperson, senior vice president of Nova Corp.

Jespersen means the referendum scheduled for Oct. 26, in which all adult Canadians will be asked to approve a set of constitutional amendments designed to keep Quebec in Canada. It is Canada's first national referendum since 1942, when voters went to the polls to say yes or no to conscription at the height of World War II.

That balloting was highly divisive, with virtually the entire French-speaking population of Quebec voting against a draft--and against the rest of the country. And the upcoming referendum promises to be no less fractious.

Already, tempers are flaring as national politicians warn that a vote against the amendments could lead to the breakup of the country, and opponents accuse the politicians of outright scaremongering.

Across Canada, all manner of peculiar things are happening as the referendum date approaches. Key civil servants have found their private telephone conversations taped and transcripts of them leaked to the media. One Quebec women's group says the government threatened to pull its funding if it didn't declare support for the constitutional amendments. A top bank economist is predicting a major recession, with 15% unemployment, if "No" wins and--as some suggest it will--Quebec then secedes from the confederation.

Even former Prime Minister Pierre Elliott Trudeau, who has largely tried to avoid the political spotlight, has jumped in, writing anti-amendment essays and delivering an eloquent speech at a Montreal restaurant with the less-than-uplifting name of La Maison du Egg Roll.

Pollsters are upon the land, in search of hints of how the vote will go. Early nationwide samples suggested a close count, but opposition to the amendments appears to be gathering force, especially in Quebec, British Columbia and here in Alberta. The French-speaking Quebecers generally think the proposed amendments don't go far enough; the English-speaking British Columbians and Albertans tend to say the changes would give too many special privileges to Quebec.

The polls also show that large numbers of Canadians are having an exceptionally difficult time making up their minds.

Throughout all the commotion, the Canadian dollar has fallen sharply. Economists have complained for several years that the currency was substantially overvalued, hurting this country's ability to export. But now that it has dropped in value against the U.S. dollar, few are cheering. Canada's political uncertainty is widely blamed for the decline.

It is economic woes like the weakening dollar that have convinced Jespersen, who says he doesn't ordinarily get involved in politics, to become co-chairman of the Yes for Canada Committee in Alberta.

"If there is a 'No' vote, for sure there will be political instability, and that will have economic consequences," he warns. "Investors just don't like political instability."

This month's referendum is the latest chapter in a constitutional saga that has been running in Canada for decades. Of Canada's ten provinces, only nine have ratified the national constitution. Quebec has held out, arguing that the document does not enshrine the autonomy it needs to protect its unique French language and culture.

Canadian Prime Minister Brian Mulroney, himself a Quebecer, though an English-speaking one, took office in 1984 promising to "bring Quebec into the constitutional family" by amending the constitution to the province's satisfaction.

His first attempt, a brace of amendments called the Meech Lake Accord, died a humiliating death two years ago when the provincial legislature in Manitoba refused to ratify it, and the one in Newfoundland threatened not to.

Now, the new package may be Mulroney's last chance, since he has to call an election next year and is faring poorly in the polls. Many Canadians thus think the stakes this time are much higher.

"It took weeks and weeks for the politicians to come to a consensus (on the new amendments)," says John Currie, a former oilman, president of the Calgary Chamber of Commerce, and another "Yes" activist. "If we found a compromise (this time) and it's not accepted, how are we going to find another one?"